1. Field of the Invention
The present invention relates to an audio reproducing apparatus for reproducing audio signals in a multi-channel audio format of a DVD (Digital Versatile Disc), such as AC-3 (Audio Code Number 3) or dts (digital theater system).
2. Description of the Related Art
Multi-channel audio formats are employed as the DVD video audio format, and 5.1 channels such as the AC-3 and dts are well known. According to the definition of such a 5.1 channel multi-channel surround system, there are employed two from left and from right channels, a front center single channel, two rear left and rear right channels and a sub woofer channel.
A multi-channel audio reproducing apparatus such as an AV (Audio visual) amplifier (A/V receivers) for reproducing a surround signal requires a maximum number of audio power amplifiers defined by the audio format. The multi-channel audio apparatus based on the 5.1 channel surround typically includes five audio power amplifiers (if no power amplifier is provided for the woofer).
A 6.1 channel audio format with a rear center extended to three channels, such as THX-EX and dts-ES, has been standardized as a multi-channel surround method.
The conventional technique based on the assumption that audio power amplifiers of the maximum number defined by the audio format are included needs modifying hardware to include six audio power amplifiers in a multi-channel audio reproducing apparatus for 6.1 channels.
However, in the method requiring power amplifiers of the number equal to the number of channels of audio format, each time the number of channels is increased, power amplifiers must be added accordingly. This method not only increases the additional cost of expensive high-power amplifiers but also assembly costs involved in the modification of hardware. The reproducing apparatus becomes costly.